After 11 years kiting in Bahia Salinas, I can say that wind is there every day from mid November 'til mid May with an average of only 1 or 2 days per month without it. Wind actually begin even before but you can get some light afternoons. Starting from mid December have a small kite is a must, cause the wind blows over 20kns mostly all the time. Between mid Jan to mid March we have the stronger winds with some days over 30kns. and it's when we sporadically use the shorty. Wind can be gusty but with a 7/9 mt kite is not a big deal.
If you rent a car you can't drive across the border with Nicaragua. If your main interest is kitesurfing you can save money staying at the Blue Dream kiteboarding Resort cause there is a free shuttle that take you to the launching spot of the kitebeach. Night life is quite, but at the lounge bar of this resort there are always all the kiters having good time watching videos on a wide screen, listening music (some times live), eating a real italian pizza (wood oven). Surfing is at Witche's rock, an hour 20 min. southern, really good spot! You need a 4X4 to get there or with a tour/taxi
Thanks costaricakite. Bought my ticket and ready to go.. Any other advice on things to do would be welcome! Will anyone be there between Dec 16-22?